Fully one-third of the older adults who experience the death of a spouse suffer from "complicated bereavement," a syndrome that shares features with both depression and post-traumatic stress disorder (PTSD). Older adults suffering from complicated bereavement are more likely to experience health-related functional problems, psychological illness, and mortality for at least three years following the death of a spouse. Despite these outcomes of one of the most common stressful events, virtually no standardized, effective, easily administered, and cost-effective programs exist, either in hospitals or in communities to treat and / or prevent complicated bereavement and its associated medical and mental health sequelae. The present R-21 proposal will address this need by developing a novel intervention for older adults suffering from complicated bereavement. Guided by data from preliminary studies with older adults and trauma victims conducted at our center, and with the help of several notable consultants and leaders in the field, a treatment manual will be developed and refined. Moreover, we will subject this intervention to preliminary evaluation using a randomized controlled 2x4 factorial design (treatment by time). Specifically, a multidisciplinary behavioral treatment will be compared to typically offered treatment (bereavement groups) at pre-treatment, post-treatment and at 3 and 6 month follow-up assessments using standardized and validated dependent measures of mental health, health related functioning, and interpersonal impairment in areas associated with "complicated bereavement." The experimental treatment is based on exposure-based psychological treatment models for PTSD and behavioral activation treatment models for major depression. The proposed treatment will incorporate methodology and findings from our current treatment outcome studies with victims of violence, as well as with findings from existing empirical intervention projects of other researchers in this area.